A genetic algorithm for a bicriteria supplier selection problem

In this paper, we discuss the problem of selecting suppliers for an organisation, where a number of suppliers have made price offers for supply of items, but have limited capacity. Selecting the cheapest combination of suppliers is a straightforward matter, but purchasers often have a dual goal of lowering the number of suppliers they deal with. This second goal makes this issue a bicriteria problem – minimisation of cost and minimisation of the number of suppliers. We present a mixed integer programming (MIP) model for this scenario. Quality and delivery performance are modelled as constraints. Smaller instances of this model may be solved using an MIP solver, but large instances will require a heuristic. We present a multi-population genetic algorithm for generating Pareto-optimal solutions of the problem. The performance of this algorithm is compared against MIP solutions and Monte Carlo solutions.     

移动IPv6中端到端Diffserv QoS上下文转移框架

提出了一种移动IPv6端到端的DiffServ上下文转移框架，采用COPS-SLS协议作为DiffServ在移动环境下的信令机制来实现端到端的域间SLS动态磋商，使用端到端的上下文转移方法来重建DiffServ上下文可以避免重新发起COPS-SLS信令，并且端到端的DiffServ上下文仅在新增加路径中的QB间进行转移。该方法能减少切换时的服务中断，当MN切换时，实时应用能迅速得到与切换前相同的转发处理。     

SARS-CoV-2 Viral Entry Proteins in Hyperandrogenemic Female Mice: Implications for Women with PCOS and COVID-19

SARS-CoV-2, the causative agent of COVID-19, infects host cells using the angiotensin I converting enzyme 2 (ACE2) as its receptor after priming by host proteases, including TMPRSS2. COVID-19 affects multiple organ systems, and male patients suffer increased severity and mortality. Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder in reproductive-age women and is characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. PCOS is associated with obesity and cardiometabolic comorbidities, both being risk factors associated with severe COVID-19 pathology. We hypothesize that elevated androgens in PCOS regulate SARS-CoV-2 entry proteins in multiple tissues increasing the risk for this population. Female mice were treated with dihydrotestosterone (DHT) for 90 days. Body composition was measured by EchoMRI. Fasting glucose was determined by an enzymatic method. mRNA and protein levels of ACE2, Tmprss2, Cathepsin L, Furin, Tmprss4, and Adam17 were quantified by RT-qPCR, Western-blot, or ELISA in tissues, serum, and urine. DHT treatment increased body weight, fat and lean mass, and fasting glucose. Ace2 mRNA was upregulated in the lung, cecum, heart, and kidney, while downregulated in the brain by DHT. ACE2 protein was upregulated by DHT in the small intestine, heart, and kidney. The SARS-CoV-2 priming proteases Tmprss2, Cathepsin L, and Furin mRNA were upregulated by DHT in the kidney. ACE2 sheddase Adam17 mRNA was upregulated by DHT in the kidney, which corresponded with increased urinary ACE2 in DHT treated mice. Our results highlight the potential for increased cardiac, renal, and gastrointestinal dysfunction in PCOS women with COVID-19.     

The effect of surface characteristics on the transport of multiple Escherichia coli isolates in large scale columns of quartz sand

Bacteria properties play an important role in the transport of bacteria in groundwater, but their role, especially for longer transport distances (>0.5 m) has not been studied. Thereto, we studied the effects of cell surface hydrophobicity, outer surface potential (OSP), cell sphericity, motility, and Ag43 protein expression on the outer cell surface for a number of E. coli strains, obtained from the environment on their transport behavior in columns of saturated quartz sand of 5 m height in two solutions: demineralized (DI) water and artificial groundwater (AGW). In DI water, sticking efficiencies ranged between 0.1 and 0.4 at the column inlet, and then decreased with transport distance to 0.02-0.2. In AGW, sticking efficiencies were on average 1 log-unit higher than those in DI (water). Bacteria motility and Ag43 expression affected attachment with a (high) statistical significance. In contrast, hydrophobicity, OSP and cell sphericity did not significantly correlate with sticking efficiency. However, for transport distances more than 0.33 m, the correlation between sticking efficiency, Ag43 expression, and motility became insignificant. We concluded that Ag43 and motility played an important role in E. coli attachment to quartz grain surfaces, and that the transport distance dependent sticking efficiency reductions were caused by motility and Ag43 expression variations within a population. The implication of our findings is that less motile bacteria with little or no Ag43 expression may travel longer distances once they enter groundwater environments. In future studies, the possible effect of bacteria surface structures, like fimbriae, pili and surface proteins on bacteria attachment need to be considered more systematically in order to arrive at more meaningful inter-population comparisons of the transport behavior of E. coli strains in aquifers.     

Scheduling contractors' farm-to-farm crop harvesting operations

The harvesting of renewable resources from an operations scheduling viewpoint is introduced, and a harvesting scenario arising in the agricultural context involving a commercial contracting enterprise that travels from farm‐to‐farm harvesting crops is discussed. This paper is an extension of previous work by two of the authors from the one‐farm to the multi‐farm case. In both cases, the duration of each operation is dependent upon the combination of constrained resources allocated to it, equipment and worker allocation is restricted, and minimum or maximum time lags on the start and completion of operations may be imposed. The present case incorporates harvesting at more than one farm and thus the sequence in which the farms are visited and the inter‐farm travel times must be taken into account. We report on a harvesting scheduling model and solution procedures designed specifically for large‐scale versions of the multi‐farm case. The computational times experienced in solving general instances of the model of small‐to‐medium practical size by a commercial integer programming package are encouraging. Greedy and tabu search heuristics, which are capable of solving problems of relatively large dimensions in reasonable computational time are also included. The authors believe that the model and the solution techniques developed represent a useful addition to the farm crop contractor's tool kit.     

Effects of Quercetin and Curcumin Combination on Antibacterial,Antioxidant, In Vitro Wound Healing and Migration of Human Dermal Fibroblast Cells

Wound healing impairment due to a postponed, incomplete, or uncoordinated healing process has been a challenging clinical problem. Much research has focused on wound care, particularly on discovery of new therapeutic approaches for acute and chronic wounds. This study aims to evaluate the effect of the combination of quercetin and curcuminoids at three different ratios on the antimicrobial, antioxidant, cell migration and wound healing properties. The antioxidant activities of quercetin, curcuminoids and the mixtures were tested by DPPH and ABTS free radical scavenging assays. The disc diffusion method was performed to determine the antibacterial activities of quercetin, curcuminoids and the mixtures against S. aureus and P. aeruginosa. The cytotoxicity and cell migratory enhancing effects of quercetin, curcuminoids and the mixtures against human dermal fibroblasts were investigated by MTT assay, scratch assay and Transwell migration assay, respectively. The results showed the synergism of the quercetin and curcuminoid combination to inhibit the growth of S. aureus and P. aeruginosa, with the inhibition zone ranging from 7.06 ± 0.25 to 8.78 ± 0.38 mm, respectively. The DPPH free radical scavenging assay demonstrated that the combination of quercetin and curcuminoids yielded lower IC₅₀ values (15.38–23.70 µg/mL) than curcuminoids alone (25.75 µg/mL). Quercetin and a 3:1 quercetin/curcuminoid mixture at non-toxic concentrations showed the ability to stimulate the migration of fibroblasts across the matrix, whereas only quercetin alone accelerated the wound closure of fibroblasts. In conclusion, the mixture of quercetin and curcuminoids at a 3:1 ratio was the best formulations for use in wound healing due to the antimicrobial, antioxidant and cell-migration-enhancing activities.     

Tuning Cerium(IV)‐Assisted Hydrolysis of Phosphatidylcholine Liposomes under Mildly Acidic and Neutral Conditions

With the goal of designing a lysosomal phospholipase mimic, we optimized experimental variables to enhance Ce^IV‐assisted hydrolysis of phosphatidylcholine (PC) liposomes. Our best result was obtained with the chelating agent bis–tris propane (BTP). Similar to the hydrolytic enzyme, Ce^IV‐assisted hydrolysis of PC phosphate ester bonds was higher at lysosomal pH (～4.8) compared to pH 7.2. In the presence of BTP, the average cleavage yield at ～pH 4.8 and 37 °C was: 67±1 %, 5.7‐fold higher than at ～pH 7.2 and roughly equivalent to the percent of phospholipid found on the metal‐accessible exo leaflet of small liposomes. No Ce^IV precipitation was observed. When BTP was absent, there was significant turbidity, and the amount of cleavage at ～pH 4.8 (69±1 %) was 2.1‐fold higher than the yield obtained at ～pH 7.2. Our results show that BTP generates homogenous solutions of Ce^IV that hydrolyze phosphatidylcholine with enhanced selectivity for lysosomal pH.     

Hepatoprotective principles of Swertia japonica Makino on D-galactosamine/lipopolysaccharide-induced liver injury in mice

The n-BuOH extract of Swertia japonica showed a significant hepatoprotective effect on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. The activity-guided fractionation led to the isolation of a new tetrahydroxanthone derivative, tetrahydroswertianolin (1), as well as two known iridoids, gentiopicroside (2) and sweroside (3). Their structures were elucidated by spectroscopic methods and chemical reactions. Of the three compounds, 2 and 3 possessed mild hepatoprotective activity at a dose range of 25-50 mg/kg, whereas, 1 exhibited potent activity in a dose-dependent manner. The hepatoprotective effect of tetrahydroswertianolin (1) was stronger than that of glycyrrhizin which was used as a positive control.     

The state analysis of NaCl in snow crab (Chionoecetes japonicus) meat examined by 23Na and 35Cl nuclear magnetic resonance (NMR) spectroscopy

To assess the contribution of NaCl to seafood tastiness, ²³Na and ³⁵Cl nuclear magnetic resonance (NMR) spectroscopy was used to determine the mobility of sodium and chloride ions in intact snow crab (Chionoecetes japonicus) leg meat. The T₁ (longitudinal relaxation time) values of both ²³Na and ³⁵Cl, obtained from inverse recovery experiments, show an evident variance with different heat‐processing methods. Heating tends to inhibit both sodium and chloride ion mobility. ³⁵Cl NMR spectra indicate that chloride exists in two different chemical states, one derived from free ions and the other from organic base complexes. © 2000 Society of Chemical Industry